The present invention relates generally to immunology and more specifically to humanized antibodies and uses thereof.
The extracellular matrix (ECM) plays a fundamental role in the regulation of normal and pathological processes. The most abundantly expressed component found in the ECM is collagen. Triple helical collagen is known to be highly resistant to proteolytic cleavage except by members of the matrix metalloproteinase (MMP) family of enzymes.
Angiogenesis and tumor growth depend on cellular interactions with the extracellular matrix. During angiogenesis and tumor invasion, both endothelial cells as well as tumor cells proteolytically remodel their extracellular microenvironment. The invasive cells then interact with this newly remodeled extracellular matrix followed by migration and invasion. To this end, a major component of the basement membrane surrounding blood vessels is collagen-IV. Moreover, collagen-I is the major component of the interestitial matrix.
One of the major detrimental consequences of the progression of cancer is metastasis beyond the site of the primary tumor. Such metastasis often requires more aggressive therapies, and once metastasis has occurred, the prognosis for survival of a cancer patient decreases dramatically.
The growth of all solid tumors requires new blood vessel growth for continued expansion of the tumors, particularly beyond a minimal size. Because angiogenesis is required for tumor growth, inhibiting angiogenesis is one approach to inhibiting tumor growth. It is therefore desirable to identify molecules that can target angiogenic vasculature. Particularly attractive molecules for targeting angiogenic vasculature are antibodies that can bind specifically to angiogenic vasculature. However, since most antibodies are developed in non-human animals such as mice, these antibodies often have undesirable immunogenic activity that limits their effectiveness for human therapy.
One approach to overcoming the detrimental properties of non-human antibodies is to humanize the antibodies by using human antibody framework region sequences spliced together with the binding domains that confer binding specificity. However, grafting of these binding domains, referred to as complementarity determining regions (CDRs), into human frameworks has often resulted in the loss of binding affinity.
Thus, there exists a need to identify antibodies specific for angiogenic vasculature and to humanize and optimize the antibodies for therapeutic purposes. The following invention satisfies this need and provides related advantages as well.